Calorimetric investigation of clustering in KTaO3-based compounds

Abstract

Heat-capacity and heat-release data are reported in K1-xNaxTaO3 for x=0, 0.08, and 0.24 at temperatures below 1 K and attributed to reorientations of the nuclear quadrupoles of Ta181. In pure KTaO3, the quadrupoles relax exponentially, whereas doping with Na at the K site introduces relaxation described by the Kohlrausch stretched-exponential function. © 1991 The American Physical Society.